Renderer|FX: Reduce halo brightness as bloom intensity grows

To avoid over-saturating halos, halo brightness is reduced as a
factor of bloom intensity.

doomsday/client/include/render/fx/bloom.h

@@ -39,6 +39,7 @@ class Bloom : public ConsoleEffect
 
     static void consoleRegister();
     static bool isEnabled();
+    static float intensity();
 
 private:
     DENG2_PRIVATE(d)

doomsday/client/src/render/fx/bloom.cpp

@@ -261,4 +261,9 @@ bool Bloom::isEnabled() // static
     return bloomEnabled;
 }
 
+float Bloom::intensity()
+{
+    return bloomIntensity;
+}
+
 } // namespace fx

doomsday/client/src/render/rend_halo.cpp

@@ -19,8 +19,8 @@
 
 #include "de_platform.h"
 #include "render/rend_halo.h"
-
 #include "render/rend_main.h"
+#include "render/fx/bloom.h"
 
 #include "gl/gl_main.h"
 #include "gl/gl_texmanager.h"
@@ -235,6 +235,14 @@ bool H_RenderHalo(Vector3d const &origin, float size, DGLuint tex,
         // Apply the global dimming factor.
         alpha *= .8f * haloBright / 100.0f;
 
+        if(fx::Bloom::isEnabled())
+        {
+            // Bloom will make bright areas even brighter, which means halos
+            // should be dimmer to compensate. Otherwise there will be
+            // oversaturation.
+            alpha *= clamp(0.1f, (1.f - fx::Bloom::intensity() * .8f), 1.f);
+        }
+
         // Secondary flares are a little bolder.
         if(secondary)
         {